pwm: renesas-tpu: Add MODULE_ALIAS to make module auto loading work

This driver can be built as module, add MODULE_ALIAS to make module auto loading
work.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c
index 03c1aa3..2600892 100644
--- a/drivers/pwm/pwm-renesas-tpu.c
+++ b/drivers/pwm/pwm-renesas-tpu.c
@@ -471,3 +471,4 @@
 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 MODULE_DESCRIPTION("Renesas TPU PWM Driver");
 MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:renesas-tpu-pwm");